RE: Differences with ADVAN3 TRANS1 and ADVAN3 TRANS4
The way the random terms are entered between the two models will affect your
results,
Eg. Etas on K's versus etas on CL,V
_____
Quoted reply history
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Paul Collier
Sent: Thursday, May 01, 2008 10:30 AM
To: [email protected]
Subject: [NMusers] Differences with ADVAN3 TRANS1 and ADVAN3 TRANS4
Please could someone explain why I get very different results when using
ADVAN3 TRANS1 to model a data set compared with using ADVAN3 TRANS4? Using
the rate constants obtained with TRANS1 for a two compartment model to
compute clearance and volume terms gives different values to those obtained
with TRANS4. I have tried using various initial estimates for the runs but
this has not solved the problem. I have listed typical outputs from Wings
for NONMEM below for each of the two ways of parameterising the two
compartment model. The objective function is considerably smaller with
TRANS1 ( -580 compared with -533).
Thanks,
Paul
Paul S. Collier
School of Pharmacy
Queen's University Belfast
Email: [EMAIL PROTECTED]
Using ADVAN3 TRANS1
THETA: ELIMINATION RATE RATE VOLUME
ETA: OMEGA
ERR: SIGMA
run209.lst -580.598 eval=209 sig=+3.4 sub=43 obs=184
CCIL=YNYN NVI1.1 PV1.0
THETA = 0.477 0.357 0.255 7.44
ETASD = 0.806846 0.000457165 0.00758947 1.40357
ERRSD = 0.242693
THETA:se% = 22.9 15.9 23.9 30.2
OMEGA:se% = 26.3 10287.1 559.0 27.7
SIGMA:se% = 23.4
MINIMIZATION SUCCESSFUL
P VAL.: 0.75E+00 0.17E+00 0.46E+00 0.88E+00
MIDAZOLAM 2-COMP RATES MODEL ADDITIVE ERROR
user 0:21.95 real 0:21.95 tcl 0:0.42
$PROBLEM MIDAZOLAM 2-COMP RATES MODEL EXPONENTIAL ERROR
$INPUT ID TIME DAT1=DROP AGE DOSE=AMT RATE DV WT BUC MDV GEN
$DATA ..\MIDAZOLAM.CSV
$SUBROUTINES ADVAN3 TRANS1
$PK
CALLFL=1
TVK=THETA(1)
K=TVK*EXP(ETA(1))
TVK12=THETA(2)
K12=TVK12*EXP(ETA(2))
TVK21=THETA(3)
K21=TVK21*EXP(ETA(3))
TVV=THETA(4)
V=TVV*EXP(ETA(4))
S1=V
$ERROR
IPRED=F
IRES=DV-IPRED
W=F
IWRES=IRES/W
Y=F*(1+ERR(1))
$THETA (0,0.5)
$THETA (0,0.5)
$THETA (0,0.5)
$THETA (0,10)
$OMEGA 0.01 0.01 0.01 0.01
$SIGMA 0.4
$ESTIMATION MAXEVAL=9999 PRINT=2 METHOD=CONDITIONAL INTERACTION
Using ADVAN3 TRANS4
THETA: CLEARANCE VOLUME1 INTERCOMPARTMENTAL CLEARANCE
VOLUME2
ETA: OMEGA
ERR: SIGMA
run213.lst -533.475 eval=380 sig=+4.5 sub=43 obs=184
CCIL=YNYN NVI1.1 PV1.0
THETA = 3.19 0.209 9.87 12
ETASD = 1.25698 0.000467974 0.00130767 0.849706
ERRSD = 0.283019
THETA:se% = 20.4 85.2 49.2 31.2
OMEGA:se% = 15.5 20821.9 6432.7 43.6
SIGMA:se% = 24.5
MINIMIZATION SUCCESSFUL
P VAL.: 0.97E+00 0.93E+00 0.80E+00 0.31E+00
user 0:33.95 real 0:33.95 tcl 0:0.52
$PROBLEM MIDAZOLAM 2-COMP CLEARANCE MODEL
$INPUT ID TIME DAT1=DROP AGE DOSE=AMT RATE DV WT BUC MDV GEN
$DATA ..\MIDAZOLAM.CSV
$SUBROUTINES ADVAN3 TRANS4
$PK
CALLFL=-1
TVCL=THETA(1)
CL=TVCL*EXP(ETA(1))
TVV1=THETA(2)
V1=TVV1*EXP(ETA(2))
TVQ=THETA(3)
Q=TVQ*EXP(ETA(3))
TVV2=THETA(4)
V2=TVV2*EXP(ETA(4))
S1=V1
$ERROR
IPRED=F
IRES=DV-IPRED
W=F
IWRES=IRES/F
Y=F*(1+ERR(1))
$THETA (0,3)
$THETA (0,0.1)
$THETA (0,1)
$THETA (0,10)
$OMEGA 0.04 0.04 0.04 0.04
$SIGMA 0.4
$ESTIMATION MAXEVAL=9999 PRINT=2 METHOD=CONDITIONAL INTERACTION
$COVR PRINT=E
_____
No viruses found in this incoming message
Scanned by iolo AntiVirus 1.5.3.5
http://www.iolo.com http://www.iolo.com/iav/iavpop3
_______________________________________
No viruses found in this outgoing message
Scanned by iolo AntiVirus 1.5.3.5
http://www.iolo.com